Palladium catalysed tandem cyclisation–anion capture processes. Part 8 [1]: In situ and preformed organostannanes. Carbamyl chlorides and other starter species

A sequential one-pot process is reported involving in situ, palladium catalysed, formation of a series of tributylstannyl-1,2-carbo and heterocyclic dialkylidene-5-membered rings from the corresponding 1,6-diynes and Bu3SnH. These substrates and other organostannanes are then combined with carbamyl chlorides and iodobenzenes containing proximate alkene and alkynyl groups in palladium catalysed cyclisation–anion capture cascades affording a diverse range of heterocycles in good yield.

Carbamyl chlorides with a proximate alkyne/alkene undergo regioselective Pd catalysed cyclisation–organostannane capture to afford lactams in good yield whilst aryl iodides with a proximal alkene undergo an analagous process with in situ generated exocyclic-dienylstannanes in good yield.Figure optionsDownload as PowerPoint slide